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Biomedical subjects

K Kasai

Publications and source records attributed to K Kasai.

At least 181 records · Page 10Linked to original sources
PubMed1995

Strain-specific presence of two TGN38 isoforms and absence of TGN41 in mouse.

TGN38 and TGN41 are isoforms of an integral membrane protein that is predominantly localized to the trans-Golgi network (TGN) in rat cells. They have been proposed to form a heterodimer and to be involved in the budding of exocytic transport vesicles from the TGN. By cDNA cloning and analysis using polymerase chain reaction, we found that there were two TGN38 isoforms in a strain of mouse (ICR), whereas other strains examined (BALB/c, DBA/2, and C57BL/6) had only one TGN38. The major difference between the two isoforms was in the number of characteristic octapeptide repeats. Apart from this, there were several nucleotide substitutions between them. The two isoforms appeared to be derived from two distinct genes but not from one gene via alternative splicing. Furthermore, we failed to show the presence of TGN41 in all the strains examined. This result suggests that TGN38 may function as a monomer or a homodimer in mouse cells.

Amino Acid Sequence↗
PubMed1995

Determination of the affinity constants of concanavalin A for monosaccharides by fluorescence affinity probe capillary electrophoresis.

Dissociation constants between a legume lectin, concanavalin A (Con A), and unlabeled neutral monosaccharides were determined by affinity probe capillary electrophoresis (APCE). An affinity probe was synthesized by coupling Lissamine rhodamine B and p-amino-phenyl-alpha-D-mannopyranoside, with glutathione as a negatively charged linker. Electrophoresis of the affinity probe was carried out at neutral pH in a fused silica capillary coated with succinylpolylysine on its inner surface, using laser-induced fluorescence detection. In the presence of Con A, the mobility of the affinity probe decreased and this decrement was analyzed as a function of the concentration of Con A. In the presence of a mixture of Con A and an unlabeled monosaccharide, APCE can thus measure the concentration of Con A unoccupied by the unlabeled monosaccharide, and this allows the determination of the dissociation constant of the Con A-monosaccharide complex. The method should be useful for the analysis of a wide range of molecular interactions on a microscale.

Concanavalin A↗
PubMed1995

The modified method of two-step differential extraction of sperm and vaginal epithelial cell DNA from vaginal fluid mixed with semen.

This investigation was undertaken as an efficient method for isolating sperm DNA from a mixed fluid sample which contains vaginal epithelial cells in a greater amount. The modified method of the two-step differential extraction procedure was found to be suitable for separating sperm DNA and vaginal epithelial cell DNA from the mixed stains. As the first step of digestion, vaginal epithelial cells in the mixed stains were lysed with Proteinase K and SDS, and sperm heads remaining in the lysed solution were collected by centrifugation. As the second step digestion, the sperm heads were lysed with the buffer containing Proteinase K, SDS and DTT as reducing agent. DNA fractions extracted from the two lysed solutions were enriched, one with sperm DNA and the other with vaginal epithelial cell DNA. MCT118(D1S80), ApoB VNTR and HLADQ alpha types of sperm DNA were detected and were confirmed by matching with corresponding male blood DNA. In the case of vaginal secretion mixed with semen of two males, the mixture of MCT118 types of the two males was detected in sperm DNA fraction.

Base Sequence↗
PubMed1995

Fluorescence-labeled peptides as isoelectric point (pI) markers in capillary isoelectric focusing with fluorescence detection.

Commercially available peptides, mostly angiotensin derivatives, were labeled at their N-terminal amino group with 5-carboxytetramethylrhodamine succinimidyl ester, to obtain fluorescent pI markers for capillary isoelectric focusing with fluorescence detection. The labeled peptides were purified by reversed-phase chromatography. They were well separated on isoelectric focusing in a polyacrylamide gel slab and their pIs were determined by comigration with protein-pI markers. The fluorescent markers could be detected as sharp peaks in capillary isoelectric focusing with laser-induced fluorescence detection (He-Ne laser, 1 mW, 543.5 nm). The detection limit was found to be around 3 x 10(-12) M (0.8 amol). Tetramethylrhodamine-labeled pea lectin (3 pg) was subjected to capillary isoelectric focusing and the pIs of the fluorescent derivatives of the lectin were determined by using the fluorescence-labeled peptides as pI markers.

Amino Acid Sequence↗
PubMed1995

Changes in expression of two endogenous beta-galactoside-binding isolectins in the dermis of chick embryonic skin during development in ovo and in vitro.

In order to elucidate the roles of metal-independent animal lectins, we systematically investigated changes in expression of 2 kinds of beta-galactoside-binding isolectins (MW 14 and 16 kDa) in the dermis of chick embryonic tarsometatarsal skin during the course of development. These lectins were immunohistochemically located at different stages of development both in ovo and in vitro by light and electron microscopy. Light-microscopic observation showed that while positive staining for the 14-kDa lectin was weak at days 8 and 10 it became intense after day 13. In contrast, staining for the 16-kDa lectin was intense at days 8, 10, and 13, but it became weak after day 17 when keratinization of the epidermis was completed. Immuno-electron-microscopic observation revealed that both the 14 and 16-kDa lectins were located on the basement membrane, in the extracellular matrix, and in both the cytoplasm and the nucleus of dermal fibroblasts. Distribution of the 2 isolectins was also examined in cultured skin explants in vitro. The results were almost the same as those obtained in ovo when the skin explant was keratinized in the presence of hydrocortisone. However, in the skin explant where keratinization was prevented and mucous metaplasia was induced by the addition of vitamin A, the distribution of the 14-kDa lectin in the epidermis was significantly affected. These results indicate that (1) the expression of the 2 isolectins is differently regulated in both the dermis and epidermis, (2) the 16-kDa lectin is involved in the early stage of the formation of the dermis and the basement membrane and is replaced by the 14-kDa lectin as keratinization of the epidermis occurs, and (3) the expression of the 2 isolectins in the dermis is not significantly affected by the induction of mucous metaplasia, in contrast to their drastic changes in the epidermis.

Animals↗
PubMed1995

Expression of the endogenous 14-kDa beta-galactoside-binding lectin galectin in normal human skin.

The localization of an endogenous 14-kDa beta-galactoside-binding lectin (galectin) and its pattern of gene expression were examined in normal human skin by light- and electron microscopy. Under the light microscope, immunostaining of 14-kDa galectin was observed in the cell membrane of cells in the basal and spinous layers of the epidermis. Galectin was also found in the Langerhans cells, as shown by double labeling using anti-14-kDa galectin and anti-CD1a antibodies. In the dermis, immunostaining for the 14-kDa galectin was positive in the extracellular matrix and fibroblasts. At the electron-microscopic level of resolution, galectin was located primarily along the plasma membrane of keratinocytes, and in both the cytoplasm and nucleus of Langerhans cells in the epidermis, whereas in the dermis it was detected in the extracellular matrix and in both the nucleus and cytoplasm of fibroblasts. The gene expression of 14-kDa galectin was visualized by the HRP-staining method following in situ hybridization techniques. The expression was detected in the cytoplasm of cells in the basal and spinous layers of the epidermis; whereas, in the dermis, it was detected in the cytoplasm of fibroblasts. Moreover, SDS-polyacrylamide gel electrophoresis and lectin-blot analysis revealed that this galectin bound to glycoproteins of approximately 17, 62, and 72 kDa in the epidermis and to those of 29, 54, and 220 kDa in the dermis. The present study indicates that 1) normal human skin produces the beta-galactoside-binding 14-kDa galectin, and 2) this galectin is located in both the epidermis, particularly in the keratinocytes and Langerhans cells, and in the dermis. These results suggest that galectin is important for cell-cell contact and/or adhesion in the epidermis and for cell-extracellular matrix interaction in the dermis.

Base Sequence↗
PubMed1995

Immunohistochemical characteristics of chicken spleen ellipsoids using newly established monoclonal antibodies.

Ellipsoids, the extra-vasculature sites surrounding penicilliary capillaries of the chicken spleen, play critical roles in the immune response and also in the clearance of pathogens or other particles. The meshwork of ellipsoids is formed by fibroblastic reticular cells. To characterize ellipsoidal reticular cells, a series of monoclonal antibodies against the chicken spleen have been developed. Of these antibodies, CSA-1 antibody reacts with fibroblastic reticular cells in ellipsoids and with endothelial cells. The reticular nature of positive cells in ellipsoids is indicated by immuno-electron microscopy, and by double staining with anti-heat-shock protein 47 kDa (hsp47) antibody. The reaction of CSA-1 with reticular cells is limited in ellipsoids; CSA-1 does not react with reticular cells in other lymphoid organs. These findings indicate that ellipsoidal reticular cells share the antigen with endothelial cells. Ontogenic studies reveal that, on embryonic day 18, the development of ellipsoids is completed, penicilliary capillaries become fenestrated, and CSA-1 expression in ellipsoids begins. These findings suggest that CSA-1 is expressed on the cell surface of ellipsoidal reticular cells once they are exposed to blood flow.

Animals↗
PubMed1995

Production of transgenic mice by microinjection of DNA into vitrified pronucleate stage eggs.

Vitrification is a technique for cryopreserving cells without crystallization due to elevation of the viscosity during the cooling process. We have developed a rapid and convenient mean of cryopreserving mouse preimplantation embryos by vitrification using a solution (hereafter named DPS) consisting of 2.75 M dimethylsulfoxide, 2.75 M propylene glycol and 1.0 M sucrose. In vitro fertilized pronucleate stage eggs were used because a large number of stage-matched eggs can be obtained at once. Only successfully fertilized eggs were collected and vitrified in DPS. After warming, two DNA constructs were injected into a total of 257 cryopreserved eggs, of which 175 (68%) survived the injection and were transferred into six recipients. All recipients became pregnant and gave birth to a total of 20 pups. When these DNA constructs were concomitantly injected into fresh eggs, 18% of eggs that were transferred developed into live pups, which was the same as the 18% figure for the cryopreserved eggs. With respect to transgenesis, 40% of the pups (8/20) developed from vitrified eggs were transgenic. In terms of the injected eggs that had been transferred, 4.5% of the 213 fresh eggs and 3.1% of the 112 vitrified eggs developed into transgenic mice. These results indicate that the efficiency of production of transgenic mice from vitrified eggs is comparable to that from fresh eggs.

Animals↗
PubMed1995

The herbal medicine sho-saiko-to induces nitric oxide synthase in rat hepatocytes.

We have examined the effects of the herbal medicine sho-saiko-to (SST) on nitric oxide (NO) biosynthesis in rat hepatocytes by measuring the stable end-product nitrite and the mRNA of inducible NO synthase (iNOS). Interferon-gamma (IFN) by itself failed to induce NO synthesis (IFN: 1-1,000 u/ml). SST also did not elicit NO synthesis at concentrations up to 300 micrograms/ml when administered alone, but dose-dependently induced NO production in the presence of IFN. Whereas SST or IFN induced barely detectable levels of iNOS mRNA when administered alone, a combination of SST and IFN markedly induced iNOS mRNA in the cells. SST also modestly increased NO synthesis caused by interleukin-1 or bacterial lipopolysaccharide as a single agent, or in combination with IFN. On the other hand, SST had no effects on the NO synthesis produced by iNOS which were already induced. Thus, we found that SST stimulates cultured hepatocytes to produce NO by inducing iNOS gene expression under appropriate conditions. The capability of SST to induce NO biosynthesis might be related to the therapeutic efficacy of SST on the liver diseases.

Amino Acid Oxidoreductases↗
PubMed1995

Effects of calcium channel antagonists on the induction of nitric oxide synthase in cultured cells by immunostimulants.

We investigated whether calcium channel antagonists would alter the induction of nitric oxide (NO) synthesis by bacterial lipopolysaccharide (LPS) alone or in combination with interferon-gamma (IFN gamma) in cultured J774 macrophages, rat vascular smooth muscle cells, rat renal mesangial cells, and rat cardiac myocytes. The induction of NO synthesis was determined by measuring nitrite, the stable end-product. The dihydropyridine calcium channel antagonists, nifedipine, manidipine, nitrendipine, benidipine, barnidipine, perdipine, and nilvadipine all reduced the LPS-induced nitrite production in a dose-dependent manner, each with a differing half-maximal inhibitory concentration, in cultured J774 macrophages. Nifedipine also inhibited nitrite production in vascular smooth muscle cells, mesangial cells, and cardiac myocytes. The half-maximal inhibitory concentrations of nifedipine were ranked as follows: smooth muscle cells < mesangial cells < cardiac myocytes. Diltiazem, at nontoxic concentrations, had no effect on the nitrite formation in the three cell types. Verapamil markedly increased the formation of nitrite in cardiac myocytes in response to LPS and IFN gamma, but not in vascular smooth muscle or mesangial cells. Exposure of cardiac myocytes to LPS and IFN gamma caused the expression of NO synthase mRNA that was significantly increased by verapamil. Thus, certain calcium channel antagonists modulate NO synthesis by altering the induction of NO synthase.

Adjuvants, Immunologic↗
PubMed1995

Do ictal, clinical, and electroencephalographic features predict outcome in West syndrome?

Ictal electroencephalographic/video recordings of 42 patients with West syndrome (WS) were reviewed to define the relation between ictal, clinical, and EEG features and etiology or prognosis. The duration and type of spasms, the number of spasms per cluster, and the interval between spasms did not correlate with the etiology or the short-term prognosis. However, eye deviation, asymmetric spasms, and partial seizures concomitant with spasms were observed only in symptomatic WS patients with poor outcome. In particular, all 8 patients with concurrent partial seizures had severe psychomotor retardation. The ictal EEG characteristics did not correlate with etiology and prognosis. There was no significant difference between the patients with persistence or reappearance of hypsarrhythmia and the patients without interspasm hypsarrhythmia.

Electroencephalography↗
PubMed1995

Different growth control of the two human thyroid cell lines of adenomatous goiter and papillary carcinoma.

To study the growth control of human thyroid cells in different stages of differentiation, we established two human thyroid cell lines of adenomatous goiter and papillary carcinoma. A 59-year-old female patient with adenomatous goiter was operated in September 1991, and a 27-year-old female patient with papillary carcinoma in May 1990. The thyroid cell lines were established by successive passage without cellular or genetic manipulations such as fusing other cell lines or oncogenic viral infection. These cell lines, human adenomatous goiter cells (hAG) and human papillary thyroid carcinoma cells (hPTC), exhibited a flattened polygonal shape and proliferated as a monolayer in cell culture. The doubling time of the hAG cells was 60 h in Ham's F12 medium supplemented with 10% fetal bovine serum, and that of the hPTC cells, 18 h in the same medium. Both cell lines expressed mRNA for TSH receptor and secreted cAMP into the medium during incubation with thyrotropin (TSH) at concentrations as low as 0.01 mU/mL. The effects of activators of protein kinase A (PKA), protein kinase C (PKC), tyrosine kinase (TK), and estradiol (E2) on proliferation of the hAG cells and the hPTC cells were assessed by measuring cellular DNA content in 24-well plates with diaminobenzoic acid. TSH stimulated proliferation of the hAG cells, but it inhibited proliferation of the hPTC cells. Since TSH activates two signaling pathways, the adenyl cyclase-PKA system and phospholipase C-PKC system, we tested effects of dibutylyl cAMP (dBC) and phorbol myristate 13-acetate (PMA), separately. dBC stimulated proliferation of the hAG cells, but it inhibited that of the hPTC cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1995

Relationship between cranial base and maxillofacial morphology.

The aims of this study were to investigate the relationships between the cranial base and maxillofacial morphology in Japanese crania, and to examine the differences between Class I and Class II samples. Data were obtained from 46 male Japanese crania from the collection of the Jikei University School of Medicine (Tokyo). The sample represents populations which would have lived during the last 100 years. A principal component analysis of linear and angular measurements showed that the anterior and posterior cranial base, and the cranial base angle were associated in different ways with different aspects of maxillofacial morphology. Variation in the anterior cranial base was associated with differences in facial height, lower facial height, bicondylar breadth, ramal height, and ramal width, while posterior cranial base length was correlated with bizygomatic breadth. The cranial base angle was negatively correlated with SNA (r = -0.46) and SNB (r = -0.59), and positively correlated with the palatal and occlusal plane angles. There were significant differences between Class I and Class II specimens in palatal width, SNA, ANB, and the palatal plane angle, but no significant difference in cranial base length or angle. The evidence suggested that cranial base shape and size was related to facial length, inclination of the maxilla, and both maxillary and mandibular prognathism.

Adolescent↗
PubMed1995

Genetic and environmental influences on facial profile.

Observed variation in facial morphology results from the influences of both genetic and environmental factors. To investigate the role of genetic influences on variation in facial profile, lateral photographs of 23 male and 19 female monozygous (MZ), and 15 male and 22 female dizygous (DZ) twin pairs were selected from the records of the South Australian Twin Study. Soft tissue landmarks and facial profiles were identified, traced and digitized. Linear and angular measures defined by the landmarks were calculated and a series of Fourier functions derived to describe the facial profiles. These Fourier amplitudes were interpreted in terms of the specific regions which they represented. Correlations within MZ pairs were consistently higher than within DZ pairs for both the facial dimensions and the Fourier amplitudes, providing evidence of significant genetic contribution to facial convexity, facial height and facial depth. Variability in nose and lip morphology appeared to be under stronger environmental influence.

Adolescent↗